Field study to detect illicit and medicinal drugs in car drivers in Southern and Western Hesse.

In the present study, immunochemical tests (Mahsan DrugInspector, DOA4, DOA8, DOA10, Protzek) as well as the detection rate of police checks were evaluated. Urine and blood samples of suspected car drivers were analysed by chromatography-mass spectrometry. Additionally, anonymised urine samples were analysed on a voluntary basis in cases where no legal proceedings were initiated. Toxicological analyses (total unknown screening) were performed using gas chromatography-mass spectrometry (GC-MS) after hydrolysis, acidic and alkaline extraction and derivatization. A data base for screening 9000 substance entries was applied. In addition, urine samples were analysed using liquid chromatography/ time-of-flight mass spectrometry (HPLC-ToF-MS) to screen psychiatric and narcotic drugs. In total, samples of 154 suspects were analysed, of these, 46 samples for no actual reason. In 5 of the latter samples, forensically relevant substances were detected; in two cases the consumption of illicit drugs, i. e. cannabis and methamphetamine, was proved. Of the 154 suspects, 108 were charged with driving under the influence of drugs; in samples of 103 of these cases, illicit drugs were found. Immunochemical pretesting showed posi- tive results in 97 of the 108 cases; in 6 samples, psychiatric drugs (citalopram, doxepin, promethazine, mirtazapine, fluoxetine, venlafaxine) were later identified, which are not detectable by ordinary pretesting systems. Police officers successfully identified 95.4 % of the suspects as drug consumers, which is an excellent result. In practice, pretesting of urine samples using immunochemical techniques proved to be very reliable. The Protzek system in particular corresponded well with the results of the chromatographic analyses. In conclusion, systematic chromatographic-mass spectrometric analysis of urine samples of suspects is recommended to identify car drivers consuming illicit drugs and to obtain data usable in legal proceedings (e. g. suspending of the driving license), which is not always possible when using blood samples in cases of drugs consumed some time ago.